// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_AUDIO_WIN_AUDIO_MANAGER_WIN_H_
#define MEDIA_AUDIO_WIN_AUDIO_MANAGER_WIN_H_

#include <memory>
#include <string>

#include "base/macros.h"
#include "media/audio/audio_manager_base.h"

namespace media {

class AudioDeviceListenerWin;

// Windows implementation of the AudioManager singleton. This class is internal
// to the audio output and only internal users can call methods not exposed by
// the AudioManager class.
class MEDIA_EXPORT AudioManagerWin : public AudioManagerBase {
public:
    AudioManagerWin(
        scoped_refptr<base::SingleThreadTaskRunner> task_runner,
        scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
        AudioLogFactory* audio_log_factory);

    // Implementation of AudioManager.
    bool HasAudioOutputDevices() override;
    bool HasAudioInputDevices() override;
    base::string16 GetAudioInputDeviceModel() override;
    void ShowAudioInputSettings() override;
    void GetAudioInputDeviceNames(AudioDeviceNames* device_names) override;
    void GetAudioOutputDeviceNames(AudioDeviceNames* device_names) override;
    AudioParameters GetInputStreamParameters(
        const std::string& device_id) override;
    std::string GetAssociatedOutputDeviceID(
        const std::string& input_device_id) override;
    const char* GetName() override;

    // Implementation of AudioManagerBase.
    AudioOutputStream* MakeLinearOutputStream(
        const AudioParameters& params,
        const LogCallback& log_callback) override;
    AudioOutputStream* MakeLowLatencyOutputStream(
        const AudioParameters& params,
        const std::string& device_id,
        const LogCallback& log_callback) override;
    AudioInputStream* MakeLinearInputStream(
        const AudioParameters& params,
        const std::string& device_id,
        const LogCallback& log_callback) override;
    AudioInputStream* MakeLowLatencyInputStream(
        const AudioParameters& params,
        const std::string& device_id,
        const LogCallback& log_callback) override;
    std::string GetDefaultOutputDeviceID() override;

protected:
    ~AudioManagerWin() override;

    AudioParameters GetPreferredOutputStreamParameters(
        const std::string& output_device_id,
        const AudioParameters& input_params) override;

private:
    enum EnumerationType {
        kMMDeviceEnumeration,
        kWaveEnumeration,
    };

    // Allow unit test to modify the utilized enumeration API.
    friend class AudioManagerTest;

    EnumerationType enumeration_type_;
    EnumerationType enumeration_type() { return enumeration_type_; }
    void SetEnumerationType(EnumerationType type)
    {
        enumeration_type_ = type;
    }

    inline bool core_audio_supported() const
    {
        return enumeration_type_ == kMMDeviceEnumeration;
    }

    // Returns a PCMWaveInAudioInputStream instance or NULL on failure.
    // This method converts MMDevice-style device ID to WaveIn-style device ID if
    // necessary.
    // (Please see device_enumeration_win.h for more info about the two kinds of
    // device IDs.)
    AudioInputStream* CreatePCMWaveInAudioInputStream(
        const AudioParameters& params,
        const std::string& device_id);

    // Helper methods for performing expensive initialization tasks on the audio
    // thread instead of on the UI thread which AudioManager is constructed on.
    void InitializeOnAudioThread();

    void GetAudioDeviceNamesImpl(bool input, AudioDeviceNames* device_names);

    // Listen for output device changes.
    std::unique_ptr<AudioDeviceListenerWin> output_device_listener_;

    DISALLOW_COPY_AND_ASSIGN(AudioManagerWin);
};

} // namespace media

#endif // MEDIA_AUDIO_WIN_AUDIO_MANAGER_WIN_H_
